Unit 6 Test Review
1. What Symbol stands for:
Name:_________________________________ Period:________
Change in: _______
mol: _______
Enthalpy: _______
mass: _______
Heat Energy: _______
2. Calorimetry is possible due to the known specific heat of _________________
3. Assign each of the following "terms" to the appropriate column in the table below:
feels warm, feels cold, releases energy, absorbs energy, l→ s,
l→ g,
g → l,
g → s,
s → g,
s→ l,
condensation, deposition, melting, sublimation, evaporation, freezing, +ΔH , -ΔH,
Exothermic:
Endothermic:
4. If you measure the average kinetic energy of a substance you are measuring the substances ______________
5. If you measure the energy transferred to a sample you are measuring the ________________
6. To convert Kelvin to Celsius you (add/subtract) 273, to convert Celsius to Kelvin you (add/subtract) 273.
Therefore, 234 K = _________ ˚C and 456 ˚C = _________ ˚K
Which temperature is higher, 250 ˚C or 400 K?________
7. Define the following terms:
Temperature:_______________________________________________________________________________
Heat: _____________________________________________________________________________________
Latent heat: ________________________________________________________________________________
Specific Heat: ______________________________________________________________________________
Heat Capacity: _____________________________________________________________________________
Equilibrium: _______________________________________________________________________________
Vapor Pressure: ____________________________________________________________________________
Triple Point: _______________________________________________________________________________
Critical Point: ______________________________________________________________________________
Endothermic:______________________________________________________________________________
Exothermic:_______________________________________________________________________________
Enthalpy:________________________________________________________________________________
8. Determine what the following points on the Phase
Diagram represent:
A: _________________________
B: _________________________
C: _________________________
D: _________________________
E: _________________________
F: _________________________
G: _________________________
9. Calculate the specific heat of a substance if it takes 6.7 J of energy to raise the temperature of 2.3 grams of
the substance by 78 K.
10. Calculate how much energy as heat is needed to raise the temperature of 4.5 moles of Helium
(Cp = 20.8 J/K • mol) by 47 K.
11. How much heat needed to completely melt 68 grams of ice to liquid?
12. How much energy is needed to heat a 87 gram sample of ice from -54 ˚C to 62 ˚C water? (3-step)
ΔHfus Ice melting = 334 J/g
ΔHvap Water boiling= 2260 J/g
Cp of water vapor = 1.89 J/g·C
Cp of water liquid = 4.18 J/g·C
Cp of water ice = 2.05 J/g·C
Selected Answers:
1.
Change in: Delta
Enthalpy: H
Heat energy: Q
Mol: n
Mass : m
2. water
3.
Exothermic:
feels warm
releases energy
l→ s
g→l
g→s
condensation
freezing
deposition
-ΔH
4. temperature
5. heat
6. subtract, add, -39 ˚C and 729 ˚K
7._______________
8.
A. solid phase
B. liquid phase
C. gas phase
D. triple point
E. melting/freezing point
F. boiling point
G. critical point
9) 6.7 = 2.3 x 7.8 x Csp
0.037 J/g x K
10) Q = 4.5 x 20.8 x 47
43992 J
11) Q = 68 x 334
22712 J
12) Q = 87 x 54 x 2.05 = 9630.9 J
Q = 87 x 334 = 29058 J
Q = 87 x 62 x 4.18 = 22546.92 J
Answer = 61235.82 J
Endothermic:
feels cold
absorbs energy
l→ g
s→g
s→ l
evaporation
melting
sublimation
+ΔH